Kybernetika

New conditions for robust stability in linear continuous and discrete-time systems are derived, when all matrices of the state-space model are perturbed by uncertain parameters and static output feedback is applied. Also, new conditions for robust stability in linear discrete-time systems with both unstructured and structured perturbations in the system matrix $A$ are derived. The analysis is based on the direct method of Lyapunov and several examples are used to illustrate the results.